Two adult fuscus Lesser Black-backed Gulls
with a third calendar year argentatus Herring Gull and a juvenile fuscus.
The upper-parts of fuscus are jet-black, they have long wings, a slender
small bill and are obvious small on average, approaching Common Gull in size.
Most adults don't start moult by early August, hence show old remiges, all
rectrices are present and the tertials and wing-coverts show no moult gaps.

The image below is an exception: this individual
started the wing-covert moult and median coverts #4-5 are missing, as is one
lower lesser scapular.